Motorworld’s paper № 32

During WWII the Moscow Motorcycle Plant was evacuated to Irbit that was producing many different types of motorcycle models, and the IMZ M-75 was one of them. This experimental model was produced in a racing and a road versions, being a prototype of the serially manufactured M-72.

IMZ M-75 assembled in 1943 was equipped with V-shape, twin-cylinder, OHV, 4-stroke engine having maximum capacity of 35 h.p. at 5100 rpm (40 h.p. with the augmented rate); it could reach the maximum speed of 170 km/h.

The high-efficiency engine was overheating very often, resulting in the middle cheek of the two-bearing crankshaft to crack; also the flanged lip would fail, with which the cylinder was affixed to the crankcase. Plant workers knew of these disadvantages and they were trying hard to overcome them.

It is difficult to figure out today just what may have been the goal for the IMZ designers in 1943. Maybe the need to create a more powerful machine for the military was their main idea during the war years, and they may have had some second-tier ideas about the motorcycle’s possible use as a sorts vehicle (please read in more detail Aleksei Popov’s article «Sports Motorcycles Using the Horizontally-Opposed Layout»). Outside of its military uses, the M-75 could have become, in the minds of its developers, a great civil machine. OHV engine widened considerably possible operational capabilities of the machine.

In the first years after the war, work on improving this model was continued. M-75 was prepared for its launch to serial production. According to the classification of that time, OHV machines were called sports vehicles, and their light-weight, boosted versions intended for competitions were called racing bikes.

The road version of the M-75 did not, however, make it to batch production, so that all subsequent work was done foir the purpose of its sports applications.

Over the whole period of production between 1943 and 1951 only 150 IMZ M-75 motorcycles were produced.


Manufacturer Irbit Motorcycle Plant, Irbit (USSR)
Years of manufacture 1943 – 1951
Quantity produced, units 150
Price
Today’s value
ENGINE AND TRANSMISSION
Type V-shape, twin-cylinder, OHV, 4-stroke type
Engine capacity, cc 746
Bore and stroke, mm 78 х 78
Engine rating 35 h.p. at 5100 rpm
Sparking Magneto M-90
Carburetor К-37 — 2 units
Batery 6 V
Clutch Double-plate, dry
Transmission 4-speed
FRAME AND WHEELBASE
Frame type Tubular, duplex, closed-type, welded
Front suspension Telescopic
Rear suspension Sprung
Brakes Drum type
Wheel size 3,75 х 19
DIMENSIONS
Length, mm
2 109
Width, mm
   727
Height, mm
   960
Wheelbase, mm
1 400
Ground clearance, mm
   135
Seat height, mm
   740
Mass, kg
   183
Gas tank size, l
     22
Maximum speed, km/h
   170
Range, km